Beta-Lactam Efficacy in Hospitalized Patients: A Systematic Review and Evidence Synthesis of Case Studies

Abstract

The increasing emergence of antimicrobial resistance continues to compromise the clinical effectiveness of beta-lactam antibiotics, particularly against multidrug-resistant Gram-negative pathogens. An evidence synthesis of published case reports and case series was conducted using PubMed, Google Scholar, and CINAHL databases. Eligible studies published in English between 2018 and 2024 reporting beta-lactam antibiotic use among hospitalized patients were included. Data extracted included patient demographics, infection types, pathogens, antimicrobial therapy, resistance patterns, adverse events, and treatment outcomes. Descriptive and thematic analyses were performed using R-Studio version 2024.09.1+394. A total of 51 publications comprising 75 clinical cases were included. Adults (37.1%) and elderly patients (31.4%) constituted the majority of cases. Sepsis (21.05%), meningitis (13.16%), urinary tract infections (7.89%), and pneumonia (6.58%) were the most frequently reported infections. In this study, Meropenem (58.80%) was the most frequently administered beta-lactam antibiotic, while vancomycin (48.20%) and ceftriaxone (41.20%) were commonly used in combination regimens. Escherichia coli (26.32%) and Klebsiella pneumoniae (13.16%) were the prevalent organisms. For multidrug-resistant infections, a combination of vancomycin and meropenem was the drug of choice in most cases. Infections associated with Gram-negative organisms like Aeromonas hydrophila, Pseudomonas aeruginosa, and Elizabethkingia anophelis were associated with the highest mortality. This observation likely reflects the limited therapeutic options available for these intrinsically resistant organisms and the severity of infections they cause, rather than differences in antibiotic efficacy. Beta-lactam antibiotics are still very important in patient care, and the rise in drug-resistant bacteria continues to diminish their therapeutic use. AST-guided diagnosis, therapy, and stewardship are important to maintain their effectiveness.